This application is a proposal to serve as the Statistical and Data Management Center of the Adult AIDS Clinical Trials Group (ACTG), in affiliation with the ACTG Central Group headed by Dr. Robert Schooley. Our overall objectives and aims are to be responsible for all statistical and data management activities of the ACTG, including: (l) providing statistical leadership in the design and analysis of ACTG studies; (2) establishing and administering a central data management system; (3) collaborating with ACTG investigators on scientific and procedural issues and long-range planning, (4) conducting data base analyses, and (5) conducting statistical research on issues central to the ACTG's mission. To ensure that our responsibilities are completed in a timely manner and yield.products of high quality, we have (I) established statistical and data management centers, each consisting of a management structure, scientific sections that parallel the ACTG's scientific committees, internal working groups, and support groups; and (2) assembled a staff of highly-qualified and experienced clinical trial specialists.